Preparation

1. In a medium bowl, mix together the ricotta, water, salt, Parmesan, and 1/2 cup of the mozzarella. Set the mixture aside.

2. Brown the beef in a large skillet set over medium-high heat until it's no longer pink, about 5 minutes, breaking up any clumps with a wooden spoon. Drain any fat, if needed. Add the zucchini. Stir in 2 cups of the pasta sauce. Reduce the heat to medium-low.

3. Top the mixture with 2 lasagna noodles, set in the center. Break 2 more noodles into medium-size pieces and fill in the edges. Gently spree the cheese mixture over the noodles. (The noodles may begin to curl in the skillet but the cheeses will hold them down.) Lay on the 2 remaining noodles. Pour the rest of the sauce into the skillet and spread it evenly, then sprinkle on the remaining cup of mozzarella.

4. Cover the skillet and simmer the lasagna over medium-low heat until the noodles are tender, about 20 minutes. Remove the skillet from the heat and let the lasagna cool for 5 minutes. Cut the lasagna into squares and serve.